Apparatus and method for heat exchangers



Dec. 22, 1931. T. K. SHERWOOD 1,838,043

APPARATUS AND METHOD FOR HEAT EXCHANGERS Filed Aug. 22, 1950 &

Patented Dec. 22, 1931 STATES N E T PATENT OFFICE THOMAS K. SHERWOOD, OF WORCESTER, MASSACHUSETTS- APPARATUS AND METHOD FOR HEAT EIXCHANGERS Application filed August 22, 1930. Serial No. 477,082.

by the liquid film on the wall of the tube through which the liquid passes. It has been found that this film furnishes an important resistance to the heat flow and this invention is designed to remove as much as possible of this film and thus secure the re sults specified.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 is a longitudinal sectional view of a part of a heat exchanger showing one of the tubes in detail, the part that is arranged to operate in accordance with this invention;

Fig. 2 is a sectional view through this tube, and

Fig. 3 is a similar sectional view showing a different way of applying the heat.

The heat exchanger is not shown in full but it involves a casing having heads and walls 11, which are tight to prevent the escape of heat and also in some cases to hold the heating liquid. In these heads are mounted several rotatable hollow journals 12 and two journals in the two heads in axial alignment support a tube 13. This tube can be provided with an electric heating coil 14. as shown in Fig. 2 or it can be heated or cooled by a body of heated or cooled liquid in the casing 11 and surrounding the tube 13, as shown in Fig. 3.

Each tube 13 is caused to revolve by pulleys 15 and belts 16 or by gearing, or any other desired way. The liquid, such as oil or any other desired liquid, flows from one tube to another through elbows 17 or the like. Suitable packing boxes are provided to prevent the escape of the liquids.

An important feature of this invention lies in the provision of a. central shaft 20 fixed at one end at 21 and supported at the other end on a spider 22 which has passages through it to allow the liquid to pass. This shaft is provided with a plurality of stationary 'baflies 23 reaching almost to theinner surfaces of the pipe 13. 'When these baffles or vanes are made helical, the rotation will cause the liquid to flow through the tube.

The fluid which it is desired to heat or cool' is made to flow continuously but slowly through the tube 13 or a series of such tubes while these tubes are rotated at a highspeed' on their own axes. The tubes are heated electrically or heated or cooled by a fluid heat ing or cooling medium'outside as shown in Fig. 3 or by means of a vapor condensing on theoutside. By rotating the tubes 13'at a high velocity, of course, a high velocity of the inner surface of the tube is'created relative to' the fluid flowing through; This tends to reduce the thickness of the liquid film that clings to the inside of the tube. The'fluid flows through the tube relatively slowly so that the press'ure'drop through'the apparatus will be small. A high rate of heat flow is obtained so that the capacity of the apparatus is high. The stationary bafiles 23 are used to prevent the rotation of the fluid by its contact with the inside of the rotating tube and keep the fluid in a relatively stationary condition as it flows slowly therethrough. Similar baffles 24 can be used outside the tubes for a similar purpose.

When using a condensing liquid to heat the tube, the liquid condensate is thrown off by centrifugal force as fast as formed. In this way the thickness of the condensate film on the outside of the tube is kept at its minimum.

Besides the tendency to promote rapid heat transfer the rotating tube reduces the tendency of solid particles to adhere to the surface of the cooling or heating tube. Thus the tendency for carbon to be deposited on the walls of the tube when the coils are heated to high temperatures, as in cracking oils, is reduced.

Although I have illustrated and described only two forms of the invention I am aware of the fact that other modifications can be made therein by any erson skilled in the art without departing rom the spirit of the invention as expressed in the claims. Therefore I do not wish to be limited in this respect 5 but what I do claim is 1. The method of heat transferring which consists in flowing the liquid to be heated or cooled through a tube, applying heat or cold to the tube, rotating the tube at a high speed and preventing the rotation of the liquid in the tube as it passesthroughit, 2. In a heat exchanger, the combination with a casing, of a tube in said casing, meansfor introducing liquid into the tubeand flowing it through the tube, means for rotating the. tube, means for preventing therotation of theliquid in thetube bycontact with the surfaeeyofthe.rotatingtube, and means for heat:- ingor cooling the tube. V 3; In, heat exchanger, the combinationwith acasing, of a tube in said casing, meansfor introducing the liquid totbe heated or cooled into-the tube and flowing-it through the tube, means vfor. rotating thetube at high speed, and meansfor preventing the rotation oiithe liquid in. the. tube by contact withthe surface o1 the rotating tube.

4.; In an apparatusfor heat exchanging, the. combination with a 1 casing having heads, 3 of hollow journals in said heads, tubes supported-by the hollow journals in opposite headsfonreceivin-g theliq-uidto be heated or cooled, means for rotating-said tubes with the journals, and stationary baflies within the 1 tubes-to prevent the rotation-0f the: liquid therein, as the tubes rotate.

In testimony, whereof I have hereunto.- afe fixed my signature,

7 THOMAS K. SHERWOOD. 

